In general, in wave detection processing of AE (Automatic Exposure) processing, AF (Automatic Focus) processing, or the like of a camera, the camera gets an optimal exposed state and a focused state by a plurality of exposures. In this manner, a plurality of exposures are performed, which takes a long time for the wave detection processing. The wave detection processing is photometric processing (for example, calculation of a brightness value) in the AE processing, or range finding processing (for example, calculation of a contrast value) in the AF processing.
An image capturing apparatus described in Patent Document 1 performs processing by separating a pixel area of a CMOS (Complementary Metal-Oxide Semiconductor) image sensor into first to eighth separation areas, and reading out image signals from the separation areas in parallel. Specifically, the image capturing apparatus reads out the image signals from analog ends, stores the image signals to the memory, and calculates an AF evaluation value simply in parallel (for example, see the specification paragraph [0028] of Patent Document 1).
In an image capturing apparatus described in Patent Document 2, there are two light sensitive areas having low sensitivity and high sensitivity for every solid state image capturing device. In this manner, upon one-time photometry (exposure), a brightness range of the signals from the light sensitive areas can be wide, and a proper exposure parameter may be acquired by one-time photometry (for example, see the specification paragraph [0004], FIGS. 2, 3 of Patent Document 2).
Patent Document 1:
Japanese Patent Application Laid-open No. 2007-281887
Patent Document 2:
Japanese Patent Application Laid-open No. 2004-56422